This invention relates generally to dispensers for dispensing sheet material. More particularly, this invention relates to a low cost roll dispenser for dispensing paper towels.
Dispensers for rolls of flexible sheet material, such as paper toweling, have been employed for a great many years. Dispensers are widely used in public lavatories to dispense paper toweling for users to dry their hands. Typically, a roll of sheet material is rotatably supported inside the dispenser cabinet. A user actuates a crank or lever that drives a feed mechanism for dispensing the sheet material. The feed mechanism typically includes a drive roller and an idle roller. The crank or lever interacts with the drive roller so that actuation of the crank or lever rotates the drive roller. Rotation of the drive roller acts to unwind the sheet material roll. The crank or lever is usually a separate mechanism from the housing of the roll dispenser.
Rolls have generally been supported inside the dispenser by a series of parts. Such parts include rollers, pulleys, hangars and the like. In addition to supporting and positioning the roll inside the dispenser, these parts were necessary to control the speed at which the roll unwound. These additional parts lead to increased expense in the manufacture and service of the dispenser.
Recently, the present inventors developed a concept for a roll supported by a ramp positioned inside the dispenser as shown in U.S. Pat. No. 6,302,351. The '351 Patent teaches a dispenser for a plurality of rolls as shown in FIG. 2. During operation, the primary roll moves down the ramp and eventually falls into a trough when its diameter reaches a set size. The '351 Patent shows a dispenser with a trough a bottom wall, an opening between the bottom wall and a lower part, a slot that allows an empty roll to fall from the trough, and a catch mechanism to catch the empty roll. As such, the '351 Patent requires a relatively complicated structure to achieve its purpose.
In addition, the structure of the '351 Patent permits the roll to move inside the dispenser without a contact point with either the ramp or the drive roller. This occurs when the roll reaches a small diameter and falls into the trough. In that position, the roll is able to move uncontrollably Such unfettered movement can lead to the roll bouncing around the inside of the dispenser. Bouncing of the roll can bunch the sheet material thereby jamming the feed mechanism. Such bouncing can also produce undesirable noise.
Accordingly, a need exists for a low cost roll dispenser that contains a minimal number of parts, thereby reducing costs associated with manufacturing and servicing of the dispenser. It would be desirable to have a roll dispenser that positions the roll so that the movement of the roll is constantly controlled without using a large number of parts.